The U.S. government was the first to announce it is temporarily barring passengers on certain flights originating in eight Muslim-majority countries from bringing laptops, iPads, cameras and most other electronics larger than cellphones in carry-on luggage. The ban is indefinite and will affect nine airlines in total. A U.S. official told The Associated Press the ban will apply to nonstop flights to the United States from 10 international airports serving the cities of Cairo in Egypt; Amman in Jordan; Kuwait City in Kuwait; Casablanca in Morocco; Doha in Qatar; Riyadh and Jeddah in Saudi Arabia; Istanbul in Turkey; and Abu Dhabi and Dubai in the United Arab Emirates.

Why are they doing it?

U.S. officials said the decision was prompted by “evaluated intelligence” about potential threats to airplanes bound for the United States. The officials would not discuss the timing of the intelligence or if any particular terror group was thought to be planning an attack. Most major airports in the United States have a computer tomography or CT scanner for checked baggage, which creates a detailed picture of a bag’s contents. The equipment can warn an operator of potentially dangerous material, and may provide better security than the X-ray machines used to screen passengers and their carry-on bags. All checked baggage must be screened for explosives.

When does it take effect?

The U.S. rules took effect Tuesday, but airlines will have until 3 a.m. EDT Saturday to implement them or face being barred from flying to the United States. The ban will thus be in effect for a meeting in Washington next Wednesday of the U.S.-led coalition against the Islamic State. A number of top Arab officials are expected to attend the State Department gathering.

Now Britain’s doing it

Britain’s government announced Tuesday it is banning electronic devices in the carry-on bags of passengers travelling to the U.K. from six countries, following closely on the U.S. ban. The government said in a statement that Prime Minister Theresa May chaired a meeting on aviation security on Tuesday in which it was agreed that new security measures would be put into effect on all inbound direct flights from Turkey, Lebanon, Jordan, Egypt, Tunisia and Saudi Arabia. Under the new arrangements, passengers on the flights “will not be allowed to take any phones, laptops or tablets larger than a normal-sized mobile or smartphone,” into the cabin.

Turkey’s transportation minister said his country was in talks with U.S. authorities on Tuesday to “stop or soften” the restriction on electronics for flights bound from Istanbul. Minister Ahmet Arslan said the ban would reduce both the comfort and number of passengers, the private Dogan news agency reported. Arslan urged the U.S. to “not confuse Istanbul with other places,” saying that Turkish authorities already take every possible security precaution. He added Turkey expects the issue to be resolved in the coming days.

It has supporters

A former Jordanian aviation security official says requiring airline passengers to place most electronics in the cargo hold means “one less headache” for security agencies. Jamil al-Qsous said Tuesday that he supports the new ban on electronic devices in carry-on bags. Al-Qsous said security measures at Jordan’s Queen Alia International Airport are among the most stringent in the region. Nonetheless, “it’s the right decision” to keep most electronics in the cargo hold and have “one less headache to be concerned” about, he said.

Canada is considering

Transport minister Marc Garneau says the federal government is taking a close look at the circumstances behind the U.S. and U.K. bans. But he stopping short of saying whether Canada will follow the lead of the two countries in banning electronic devices from flights originating in certain countries in the Middle East and Africa. “We will be reviewing the information that has been provided,” Garneau said Tuesday after the government’s weekly cabinet meeting. “We are looking at the information that has been presented to us we will look at it very carefully. … There is not a specific timeline; we are acting expeditiously.”